Grinder for segment rolls

ABSTRACT

A grinder for grinding segment rolls to be used for rolling spiral drill grooves, wherein a crank driven by the headstock spindle is connected to the base through a telescopic link, the headstock being spring urged toward a stop and carried on a rotatable bracket.

United States Patent (72] Inventor Marian Mlchalczyk [50] Field of Search 51/46, 65, Katowice, Poland 1 I5, 24, 234, 96 [2|] Appl. No. 775,704 221 Filed Nov. 14, 1968 References Cited [45] Patented June 29, 1971 UNITED STATES PATENTS 1731 Asslgnee 9 886,3 l0 4/1908 Wennslrom 51/234 ux Katowice, Zelazna, Poland Primary Examiner-Othell M. Simpson Attorney-lrvin A. Lavine [54) GRINDER FOR SEGMENT ROLLS 3 Chums 3 Drawmg ABSTRACT: A grinder for grinding segment rolls to be used (52] U.S. Cl 51/96, for rolling spiral drill grooves, wherein a crank driven by the 5 1/234 headstock spindle is connected to the base through a telescop- [Si] Int.Cl B24b 7/00, ic link, the headstock being spring urged toward a stop and B24b 9/00, B24b 47/02 carried on a rotatable bracket.

PATENTED JUN29 mm HGI GRINDER FOR SEGMENT ROLLS Grinders are known which have a powered headstock for a workpiece and for an abrasive wheel connected with the housing by means of links, such as positioners or hand and master controlled mechanisms. For grinding segment rolls to be used for the rolling of spiral drill grooves, of the previously mentioned grinders, those most commonly used are grinders with either a master pattern or a hand controlled connection of the headstocks with the housing. With either these types of grinding apparatus segment rolls are produced having a curvilinear nonrepetitive and out of proportion change of the calibrating profile of the segment roll.

Attempts to correct the profile thus obtained through wearisome, elaborate hand grinding had no significant influence on remedying those faults and may even lead to deterioration of the shape produced. As a result, the spiral drills rolled with such rolls lack a symmetrical and uniform grooving and so do not provide optimum machine properties. The calibrating part of a roll segment profile, which is the part which contacts the material being rolled, which approximates a straight line, can be obtained from grinders provided with a master control mechanism for the headstock. However, grinders of that type have not found wide application, primarily because of the difficulty in obtaining a suitable pattern and because of a rather complicated construction of the mechanism.

The object of the present invention is to provide a grinder without a pattern of simple and efficient construction, for producing a reproducible straight line, and proportionally altering profile of the calibrating part of the segment roll.

A grinder in accordance with the present invention is shown in the attached drawing wherein: FIG. I is a plan view of the present invention grinder.

FIG. 2 is a diagram showing the principle of operation of the grinder.

FIG. 3 is a side view of the grinder.

As can be seen in FIGS. 1-3 the grinder comprises housing 1, headstock 2, and abrasive wheel 3. The headstock 2 for the workpiece is carried on a rotatable bracket 4, with spring 5 and link 6 connecting it to a housing 1. The link 6 comprises a telescopic arm 7 fastened by means of a grip 8 to the crank 9 coupled with the rotary spindle 10 of the headstock. A stop 11 is fastened to the housing I. The grip 8 coupled with the headstock drive (not shown in the drawing) rotates in a circular path whose direction and position is indicated by the arrow aThe rotary motion of the grip 8 from point A." to point B results in lengthening of the telescopic arm 7. At point "B the arm 7 approaches its longest position. As a result of a further motion of the grip 8 between points 8" and A," the grip 8 transfers a swinging motion in the direction indicated by At point A" the headstock 2 comes into contact with the stop I] and the cycle ofgrip operation is repeated.

Before starting the grinding operation, the segment roll 12 is mounted in the headstock 2 and the abrasive wheel 3 is pressed against the roll 12 at point D" (FIG. 3) which lies on the axis of rotation I3 of the bracket 4 and the crank 9; the stroke of the arm 7 and the position of stop 11 are preset for the required parameters.

Grinding of the roll profile 12 is done during the motion of the grip 8 along the arc BC". At that time the segment roll I2 has a rotary motion about axis 10 on path a" and a swinging motion on line b about axis 13. As a result of those movements, the abrasive wheel 3 grinds the roll 12 to a precise proportionally altering, straight line surface.

Depending upon the preset stop 11, the stroke of arm 7 and the crank length 9, the position of points A, B and C are subject to change and so is the motion of the headstock 2 while changing from one roll-diameter to another requires only a suitable setting of the roll against the abrasive wheel. Due to this fact, different lgrinding parameters of various rolls suitable for spiral dI'IllS of lfferent diameters, lengths and dimensions of groove selections can be obtained while using one grinder only.

The grinder according to the present invention ensures obtaining by a simple construction segment rolls which facilitate reproducible production of spiral drills of identical dimensions and good surface finish and meeting the dimensional and shape standards of spiral drills having the best machining properties.

Iclaim:

1. A grinder for segment rolls comprising:

a housing,

a bracket, a headstock supported by said bracket, pivot means externally of said headstock rotatably supporting said bracket on said housing,

a grinding wheel positioned to engage a workpiece carried in said headstock,

a spindle in said headstock, a crank connected to said spindle, and a telescopic arm connected to said crank and to said housing to thereby impart an oscillating movement to said headstock about said pivot means,

a stop for limiting rotary motion of said headstock and bracket,

and spring means urging said headstock towards said stop.

2. The grinder of claim 1, wherein said crank is at one end of said headstock and said grinding wheel is adjacent the opposite end thereof.

3. The grinder of claim I, said telescopic arm being adjustable. 

1. A grinder for segment rolls comprising: a housing, a bracket, a headstock supported by said bracket, pivot means externally of said headstock rotatably supporting said bracket on said housing, a grinding wheel positioned to engage a workpiece carried in said headstock, a spindle in said headstock, a crank connected to said spindle, and a telescopic arm connected to said crank and to said housing to thereby impart an oscillating movement to said headstock about said pivot means, a stop for limiting rotary motion of said headstock and bracket, and spring means urging said headstock towards said stop.
 2. The grinder of claim 1, wherein said crank is at one end of said headstock and said grinding wheel is adjacent the opposite end thereof.
 3. The grinder of claim 1, said telescopic arm being adjustable. 